Mold for the casting on of shafts for twist drills and similar tools



` A. F. DRssl-:L

MOLD FOR THE CASTING ON OF SHAFTS FOR TWIST DRILLS AND SIMILAR TOOLSFiled Ami. 29. 1921 Dec. 4 1923.

` l I nventor.

Patented Dec. 1, 1923.

res

,PATENT o asics.

\ i @Donn FRIEDRICH genossen'v or MANNHEIILGEHIJIANY, nssIenon ToiTHECORPORA- aTIoN OFTHITZ NnUMnYna AKTIENGESELLSCHAFT, or NUREMBEHG,GERMANY.

nroinroa THE casTING onl or sHaTTsIoza TWIST nnILLs Ann :SIMILAR Toons.

Application -led August y29,192 1. :Serial No. 496,454.

T @ZZ fw 720m t may concern yBe It known that I, `finoni FRIEDRICH,Dnssnn engineer, a citizen of the German Republic, and residentatMannheim, Germany, with the post-office address Collini- `strasse 31,have invented certain new and` useful Improvements in yMolds for theCasting on of Shafts forTwist Drills andSiInilar Tools (orwhich I havefiled applica tion` in Germany, March 6th, 1920) 'and T do herebydeclare the following to be a full,`

clear, and exact` description ot the invention,such will enable rothersskilled in the art to which it appertains to make and use the same.

This` invention relates `to a mold with cen- `tering device designed forproviding twist i drills, especially broken twist .drills with y mold ofthe second form of construction.

9 is the casting mold made in one piece which forms a thick-walled,jointless, cylindrical hollow body whose innerspace 1() correspondsexactly withthe shape of the drill shaft to be produced and to becast-on. Fig. 1 shows a conical inner space.

The centering device is formed b-y a disk 11 and by the centering sleeve12. The centering sleeve 12 and the disk 11 are exactly con-axial withthe casting mold 9. The disk joins the end tace of the casting mold andit is provided with a ring flange 13 having a thread 14, so that the twoparts can be easily and securely connected the one with the other andthat no metal can flow out between the surfaces of the casting mold andot the disk which join one another tightly. For drilling tools whoseshapes diiler very much, the disk and the casting mold are dimensionedcorrespondingly. As the shaft of reamer bits and similar tools are oftenflattened at the tree end to form a spike a corresponding cavity 15 isarranged in the casting mold in a disk 16 which closes the inner space10. A lling ring 17 serves as funnel for pouring. inthe liquid metal. fY' The centering sleeve is rigidly but removably connected with the disk11 by a thread 1S lso that it can be exchangedftor a centering sleeve ofother inner width. The. sleeve "12 has two opposite slits 19. A clampingring 20'with two clamping screws 'for securing the centered tool in itsposition is placed ,upon the'sleeve 12. y

The remainder or' the tool 22 is yinserted 4in the manner shown by thedrawing into the centering device whereupon the casting mold isconnected with said centering deA vice, the funnellput in place and theliquid metal poured in. All the parts' of the device consist each ofasingle body, and they can be turned on the lathe andl bored .exactlycon-axially without difficulty and with absolute security. c

The t'orm of. construction which has just `been described requires aspecial casting mold with a cylindrical hollow space it a cylindricalshaftV has to be cast on.

The second form of construction of the casting mold shown on 3 permitsto use one and the same casting mold 9 tor the casting on ot conical and,of cylindrical shaits. 71th this object in view an Insertion. sleeve 23with conical outer surface and .cylindrical .boringis provided. llxhenthe sleeve 23 is removed from the casting mold 9 a conical shat't can benoduced and when the sleeve is inserted a cylindrical shaft can beproduced. The boring of sleeve 23 could be conical, in which case theboring ot' the casting mold ought tor be cylindrical.

Tn order to enable that with one and the same device tools can betreated whos-e shapes diii'er more, the centering plate 15 (Fig. 5) hasa lower boring which is larger on the other hand for securing the sleevein the position which it adopts when the disk 11 is screwed upon thecasting mold It' now a drill of larer size has to be repaired theauxiliary sleeve 2a and the` centering sleeve 12 are removed from plate11 and a wider centering sleeve is inserted instead in the disk.Insertion sleeves 23 of various diameters and with various borings canbe inserted in the casting mold 9 so that one and the same casting moldcan be used for tools of different sizes.

'A convenient alloy consists of zinc 90%, aluminium 3%, copper 2% and of5% of approximately equal parts of antimony, lead and tin. v

Claims:

l. An improved casting mold for the casting on of shafts of twist drillsor similar tools, comprising in combination a casting mold having acylindrical bore, a centering device for the drill also having acylindrical bore and means for rigidly but removably connecting the twoparts.

2. An improved casting mold for the casting on of shafts of twist drillsor similar tools, comprising in combination a cylin* drical case whichencloses the mold for the shaft, a disk with screw threads to be screwedupon said cylindrical case, and a centering sleeve connected with saiddisk.

3. An improved casting mold for the casting on of shafts of twist drillsor similar tools, comprising in combination a cylindrical case whichencloses the mold for the shaft, a disk with screw threads to be screwedupon said cylindrical case, and a centering sleeve removably connectedwith said disk by a screw thread.

4.-. An improved casting mold for the casting on of shafts of twistdrills or similar tools, comprising in combination a cylindrical casewhich encloses the mold for the shaft, a disk with screw threads to bescrewed upon said cylindrical case, a slotted centering sleeve connectedwith said disk, and a clamping device for compressing the two halves ofsaid centering sleeve separated by said slit.

5. An improved casting mold for the casting on of shafts of twist drillsor similar tools, comprising in combination a cylindrical body enclosingthe mold for the shaft, a disk with centering sleeve positioned at oneend of said mold and a disk adapted to be eccentrically placed upon theother end of the casting mold and provided atits center with arectangular opening.

6. An improved casting mold for the casting on of shafts of twist drillsor similar tools, comprising in combination a casting mold having avcylindrical bore, a centering device for the drill also having acylindrical bore, means for rigidly but removably connecting the twoparts', and a filling ring serving as funnel for pouring in the liquidmetal connected with said casting mold.

7. An improved casting mold for the casting on of shafts of twist drillsor similar tools, comprising in combination a casting mold having acylindrical bore, a centering device for the drill also having acylindrical bore, means for rigidly but removably connecting the twoparts, and an insertion sleeve to be inserted in said casting mold.q

8. An improved casting mold for the casting on of shafts of twist drillsor similar tools, comprising in combination, a casting mold having acylindrical bore, a removable base for said mold, a circular openingthrough said base concentric with the bore of said mold, a centeringdevice also provided with a cylindrical bore adapted to be positionedand secured within said concentric opening of the base and an auxiliaryannular sleeve interposed between said centering device and base.

In testimony whereof I aiiiX my signature.

FRANZ LEINMYER, MAv STRAUSS.

